Files
Arquivotheca.Solaris-2.5/cmd/head/head.c
seta75D 7c4988eac0 Init
2021-10-11 19:38:01 -03:00

145 lines
2.8 KiB
C
Executable File

/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
/* The copyright notice above does not evidence any */
/* actual or intended publication of such source code. */
/* Copyright (c) 1988, Sun Microsystems, Inc. */
/* All Rights Reserved. */
#ident "@(#)head.c 1.10 94/12/06 SMI" /* SVr4.0 1.1 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <locale.h>
#include <string.h>
#include <ctype.h>
#define DEF_LINE_COUNT 10
static void copyout(int);
static void Usage();
/*
* head - give the first few lines of a stream or of each of a set of files
*
*/
main(int argc, char **argv)
{
int fileCount;
int around = 0;
int i;
int opt;
int linecnt = DEF_LINE_COUNT;
int error = 0;
(void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */
#endif
(void) textdomain(TEXT_DOMAIN);
/* check for non-standard "-line-count" option */
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "--") == 0)
break;
if ((argv[i][0] == '-') && isdigit(argv[i][1])) {
if (strlen(&argv[i][1]) !=
strspn(&argv[i][1], "0123456789")) {
(void) fprintf(stderr, gettext(
"%s: Badly formed number\n"), argv[0]);
Usage();
}
linecnt = (int) strtol(&argv[i][1], (char **)NULL, 10);
while (i < argc) {
argv[i] = argv[i + 1];
i++;
}
argc--;
}
}
/* get options */
while ((opt = getopt(argc, argv, "n:")) != EOF) {
switch (opt) {
case 'n':
if ((strcmp(optarg, "--") == 0) || (optind > argc)) {
(void) fprintf(stderr, gettext(
"%s: Missing -n argument\n"), argv[0]),
Usage();
}
linecnt = (int) strtol(optarg, (char **)NULL, 10);
if (linecnt <= 0) {
(void) fprintf(stderr, gettext(
"%s: Invalid \"-n %s\" option\n"),
argv[0], optarg);
Usage();
}
break;
default:
Usage();
}
}
fileCount = argc - optind;
do {
if ((argv[optind] == NULL) && around)
break;
if (argv[optind] != NULL) {
(void) close(0);
if (freopen(argv[optind], "r", stdin) == NULL) {
perror(argv[optind]);
error = 1;
optind++;
continue;
}
}
if (around)
(void) putchar('\n');
if (fileCount > 1)
(void) printf("==> %s <==\n", argv[optind]);
if (argv[optind] != NULL)
optind++;
copyout(linecnt);
(void) fflush(stdout);
around++;
} while (argv[optind] != NULL);
return (error);
}
static void
copyout(cnt)
register int cnt;
{
char lbuf[BUFSIZ];
while (cnt > 0 && fgets(lbuf, sizeof (lbuf), stdin) != 0) {
(void) printf("%s", lbuf);
(void) fflush(stdout);
cnt--;
}
}
static void
Usage()
{
(void) printf(gettext("usage: head [-n #] [-#] [filename...]\n"));
exit(1);
}